The proposed work will investigate the molecular structure of isolated gap junctions isolated from mouse liver. Techniques include; electron microscopy, x-ray diffraction, polyacrylamide gel electrophoresis, and amino acid analysis. Gap junction structure and function will be investigated also in the mammalian lens, both in isolated preparations and in tissue culture. Junctional physiology will be assayed using autoradiography in metabolic cooperation experiments, and whole tissue autoradiography.